The objectives of this proposal are to investigate the control of glycerolipid metabolism in cultured cells and to apply cell culture systems to the investigation of hyperlipoproteinemias. Studies on the contorl of lipid synthesis center on lipid synthesis from acetate. The role of the enzyme acetyl-CoA synthetase, and the cellular uptake of acetate will be investigated. Regulation of synthesis will also be compared in fibroblast cultures atdifferent passage levels. The effect of hypertriglyceridemic sera on the glycerolipid metabolism of human diploid fibroblast cultures will be assessed. Conversely, skin fibroblast cultures from patients with hypertriglyceridemias will be studied to determine if abnormalities of cellular glycerolipid biosynthesis or utilization occur in this disorder.